Properties of monoclinic wolframite structure InWO4 for efficient and sustainable photocatalytic hydrogen evolution

Abstract

This is the first report on the application of InWO₄ nanospheres in the field of photocatalysis. Tungstates have excellent thermal and chemical stability; in this work, we have successfully prepared an InWO₄/CdS composite catalyst. Since the CB of InWO₄ is more negative than that of CdS, InWO₄ can act as a cocatalyst to promote the separation and transfer of photogenerated charges, thereby suppressing the recombination of photogenerated electron–hole pairs and significantly improving the performance of the InWO₄/CdS composite, and the hydrogen production rate of InWO₄/CdS reached 6146.63 μmol g⁻¹ h⁻¹, which was about 4.21 times that of pure CdS. Especially, the InWO₄/CdS composite exhibits high photocatalytic stability. In addition, these properties are well characterized by SEM, TEM, XRD, XPS, UV-vis, BET, transient photocurrent and FT-IR analyses etc., and all the results showed good consistency with the hydrogen production experiment.